Carburetor for internal combustion engines

ABSTRACT

A carburetor for an internal combustion engine having a bypass channel around a throttle valve and means to adjust the flow in the channel.

United States Patent [50] Field of Rudolf Beckmann [72] Inventor Wolisburg, Germany 803,273

[5 6] References Cited] UNITED STATES PATENTS App]. No. [22] Filed mmn mm "8 n" i 1 m mmm m m EABWW 5788 66666 99999 1111... 285 3 1 9 4 7 3 ABSTRACT: A carburetor for an inlemal combustion engine having a bypass channel around a throitle valve and means to adjust the flow in the channel.

n O B a W & e n M d mm mm rn mm 3 WW y m mm mm Feb. 28, 1969 [45] Patented Sept. 28, 1971 [73] Assignee Volkswagenwerk Aktiengeselisehait Wolfsburg, Germany [32] Priority Mar. 1, 1968 [33] Germany [31] P 16 01994.6

[54] CARBURETOR FOR INTERNAL COMBUSTION ENGINES 2 Claims, 3 Drawing Figs.

261/41 D F02m 3/00 PATENTED SEP28 l9?! M 31 min xam M wu CMe ggdw CARBURETOR FOR INTERNAL COMBUSTION ENGINES This invention relates to a carburetor for internal combustion engines having a flap valve with a bypass channel. It should be possible for control of the air flow that the proportional characteristics shall remain unchanged so that the ratio as to the mixture shall also be adjustable. It is therefore an object of the invention to provide a bypass channel in the carburetor so that the operative cross section of the bypass channel can be changed as well as the operative entry opening for the channel.

Further objects will be apparent from the following description when considered in connection with the accompanying drawing in which;

FIG. 1 is a longitudinal section of the carburetor or fuel injector,

FIG. la, is a sectional view of a modified detail of the mixture-entry bore, and

FIG. 2 is a longitudinal section of a modified carburetor.

The circulation or bypass channel 1 passes around the throt tle flap or valve 2. The streaming technically operating cross section of the flow can be changed or adjusted by a setting or adjusting screw 3. By means of the setting screw 3 a regulating screw 4 is guided therein which cooperates with a connecting bore 5 to more or less free the connecting bore as to the bypass channel 1. When the setting screw 3 is held in place or motionless, the regulating screw 4 can be adjusted so that the composition or combination at the mouth 6 will be changed as to the fuel-air mixture. Upon changing the amount of the mixture by means of the adjusting screw 3, the mixture proportion or relation can be adjusted so that the mixture proportions (relative to air) can be maintained, since the outlet opening of the mixing bore 5 is in the bypass channel 1 and thereby the amount of fuel can be adjusted in the same proportions as the amount of air'.

ln the construction according to FIG. 1, the bypass channel 1, upon the complete closing of the valve 2, will deliver the entire running load mixture. The throttle flap 2 can be adjusted to also permit a constant air-through flow and a constant or fixed mixture relationship. in this case, a mixture outlet opening 7 must be additionally provided, FIG. la. The smaller mixture for the mixture-outlet bore 7 must now be additionally provided over the bypass channel 1. The necessary mixture proportion will also be adjusted by means of the regulating screw 4.

In the form of the structure of FIG. 12, the throttle flap valve is set in accordance with constant air-through flow-setting or composition. The setting screw 3 and regulating screw 4 are together provided in a part 3' and this permits only a change in the amount of the mixture; not however a proportional mixture. The mixture relationship is adjusted by means of the regulating screw 8 which in its cross section will change the outlet-mixture bore 7.

Iclaim:

l. A carburetor comprising a housing including a main induction conduit having a throttle valve therein, an air bypass channel bridging around said throttle valve, an idling fuel passage in said housing and having an outlet opening in said bypass channel, and an adjustable regulating device projecting into said channel as well as into said outlet opening and operable to simultaneously change the flow cross sections of said channel and said outlet opening in a manner whereby the quantity of idling fuel-air mixture supplied to the engine may be varied without changing the mixing ratio of such mixture.

2. A carburetor according to claim 1 in which the regulating device is provided with an outside adjusting screw projecting into the channel and an inside adjusting screw guided in a thread in the outside adjusting screw and protruding into the outlet opening of the fuel passage and adjustable in order to change the mixing ratio independently of the outside adjusting screw. 

1. A carburetor comprising a housing including a main induction conduit having a throttle valve therein, an air bypass channel bridging around said throttle valve, an idling fuel passage in said housing and having an outlet opening in said bypass channel, and an adjustable regulating device projecting into said channel as well as into said outlet opening and operable to simultaneously change the flow cross seCtions of said channel and said outlet opening in a manner whereby the quantity of idling fuel-air mixture supplied to the engine may be varied without changing the mixing ratio of such mixture.
 2. A carburetor according to claim 1 in which the regulating device is provided with an outside adjusting screw projecting into the channel and an inside adjusting screw guided in a thread in the outside adjusting screw and protruding into the outlet opening of the fuel passage and adjustable in order to change the mixing ratio independently of the outside adjusting screw. 